altr,dw-mshc-ciu-div and altr,dw-mshc-sdr-timing are neither documented
nor used by Linux, so remove them to fix dtbs_check warnings like:

  socfpga_stratix10_swvp.dtb: mmc@ff808000: Unevaluated properties are not allowed
    ('altr,dw-mshc-ciu-div', 'altr,dw-mshc-sdr-timing' were unexpected)
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>